Absfmet-It is demonstrated that the reflectance function R(@) of a liquid-solid interface can be obtained by inverting the complex V(z) data collected with an acoustic microscope. The inversion algorithm is based on a nonparaxial formulation of the V(z) integral, which establishes the Fourier transform relation between R(@) and V(z). Examples are given to show that with this measurement technique, the acoustic phase velocities of the propagating modes in the solid medium can easily be determined and material losses can be estimated. The same technique is also used for characterizing imaging performance of focused systems. Applications In thin-6lm measurement are also discussed.
{"title":"Material Characterization by the Inversion of V(z)","authors":"K. Liang, G. Kino, B. Khuri-Yakub","doi":"10.1109/T-SU.1985.31587","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31587","url":null,"abstract":"Absfmet-It is demonstrated that the reflectance function R(@) of a liquid-solid interface can be obtained by inverting the complex V(z) data collected with an acoustic microscope. The inversion algorithm is based on a nonparaxial formulation of the V(z) integral, which establishes the Fourier transform relation between R(@) and V(z). Examples are given to show that with this measurement technique, the acoustic phase velocities of the propagating modes in the solid medium can easily be determined and material losses can be estimated. The same technique is also used for characterizing imaging performance of focused systems. Applications In thin-6lm measurement are also discussed.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"327 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121581378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Special Issue on Acoustic Microscopy","authors":"S. Bennett","doi":"10.1109/T-SU.1985.31578","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31578","url":null,"abstract":"","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125175111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W HEN I was first asked to write for this special issue, I was occupied with the reorientation of our entire research program and another article on acoustics seemed like a diversion. I resisted. But the editors were very persuasive, and the special issue has proved to be irresistible. The articles of this issue form a set that is complete, but but there are a few points that can be added to fill in some of the background. This is an opportunity to talk with a special audience, to acknowledge the contributions from those who have worked with us along the way, and to express our appreciation for the people who have provided the funds. Those people in Washington and in the foundations who work so hard to fund research programs make it all possible. There is little that could have been accomplished without them. In London during the month of July 1984, manufacturers exhibited their prototypes of the commercial instruments. 1984 was a milestone year for acoustic microscopy, for the information gathered with these new models outweighs anything that has appeared before. Each of the prototypes will incorporate the essential concept that we have been exploiting for several years; the concept of a single spherical lens concentrating the energy from a large source to a narrow waist with a size determined by the acoustic wavelength. This type of lens does not suffer from spherical aberrations; it is diffraction limited . The original motivation for our work came from the biologists. We were told that it was a matter of some importaye to improve the resolution beyond the limit of 3000 A set by the optical instrument with a water immersion lens. They suggested a factor of two for the improvement. It will be some time before we know whether that is true. In the meantime, the instruments will be used in fields other than biology. I suspect that polymer chemists will be the first to acquire the commercial acoustic instruments, just as they were first to acquire the scanning electron microscopes (SEM). Why did it take so long to reach this stage? That is the interesting question. Certainly the technology was available. Sokolov’s suggestion goes back 35 years. I think that part of it may have been our own inhibitions or misconceptions. One misconception is that the image must be presented in real time, 30 frames per second, as defined by the tel-
{"title":"Acoustic Microscopy: Recollections","authors":"C. Quate","doi":"10.1109/T-SU.1985.31579","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31579","url":null,"abstract":"W HEN I was first asked to write for this special issue, I was occupied with the reorientation of our entire research program and another article on acoustics seemed like a diversion. I resisted. But the editors were very persuasive, and the special issue has proved to be irresistible. The articles of this issue form a set that is complete, but but there are a few points that can be added to fill in some of the background. This is an opportunity to talk with a special audience, to acknowledge the contributions from those who have worked with us along the way, and to express our appreciation for the people who have provided the funds. Those people in Washington and in the foundations who work so hard to fund research programs make it all possible. There is little that could have been accomplished without them. In London during the month of July 1984, manufacturers exhibited their prototypes of the commercial instruments. 1984 was a milestone year for acoustic microscopy, for the information gathered with these new models outweighs anything that has appeared before. Each of the prototypes will incorporate the essential concept that we have been exploiting for several years; the concept of a single spherical lens concentrating the energy from a large source to a narrow waist with a size determined by the acoustic wavelength. This type of lens does not suffer from spherical aberrations; it is diffraction limited . The original motivation for our work came from the biologists. We were told that it was a matter of some importaye to improve the resolution beyond the limit of 3000 A set by the optical instrument with a water immersion lens. They suggested a factor of two for the improvement. It will be some time before we know whether that is true. In the meantime, the instruments will be used in fields other than biology. I suspect that polymer chemists will be the first to acquire the commercial acoustic instruments, just as they were first to acquire the scanning electron microscopes (SEM). Why did it take so long to reach this stage? That is the interesting question. Certainly the technology was available. Sokolov’s suggestion goes back 35 years. I think that part of it may have been our own inhibitions or misconceptions. One misconception is that the image must be presented in real time, 30 frames per second, as defined by the tel-","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122214615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstmct-An important ultrasonic propagation property for tissue characterization is the speed of sound. The scanning laser acoustic microscope (SLAM) provides the capacity to determine the speed of sound in tissue specimens or portions of specimens on the submillimeter scale. This capability potentially can be utilized to develop indices that quantify the spatial gradient of the tissue’s speed of sound. An automated technique for determining the speed of sound using the SLAM has been developed. It is now possible to study quantitatively the degree of tissue heterogeneity from SLAM measurements of the speed of sound distribution. T
{"title":"Spatial Distribution of the Speed of Sound in Biological Materials with the Scanning Laser Acoustic Microscope","authors":"P. Embree, K. Tervola, S. Foster, W. O’Brien","doi":"10.1109/T-SU.1985.31601","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31601","url":null,"abstract":"Abstmct-An important ultrasonic propagation property for tissue characterization is the speed of sound. The scanning laser acoustic microscope (SLAM) provides the capacity to determine the speed of sound in tissue specimens or portions of specimens on the submillimeter scale. This capability potentially can be utilized to develop indices that quantify the spatial gradient of the tissue’s speed of sound. An automated technique for determining the speed of sound using the SLAM has been developed. It is now possible to study quantitatively the degree of tissue heterogeneity from SLAM measurements of the speed of sound distribution. T","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127865530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A 1WMHz acoustic microscope using an integrated grat- ing acoustic scanner is studied. The resolution of the system is approx- imately 68 pm. The real-time acoustic images obtained from this mi- croscope demonstrate the feasibility of the approach. The dependency of the energy velocity of acoustic waves on the propagation direction in the saggital plane of a Y-cut Z-propagating LiNbO, crystal was studied, and piezoelectric effects were included. The energy of velocity disper- sion was calculated and the results were employed for designing the tap positions of a large time-bandwidth product, nonlinear chirp fflter to obtain a large aperture and spherical aberration-free operation. Theoretical analysis reveals that for a given chirped waveform, the sur- face acoustic wave (SAW) propagating in the positive 2 direction gives better resolution than that in the negative 2 direction. Focusing the bulk acoustic wave in the transverse direction is achieved with the curved grooves or metallic strips, and the focus phase error using the curved structure are studied. to reduce the attenuation loss, and the crystals used are normally anisotropic. We had also previously reported a high-frequency GAS device (8) and demonstrated its fo- cusing and scanning capabilities. Electronic focusing in the axial direction was augmented by transverse focusing using an external lens that was massive and bulky. This device was operated at a rather high frequency, approximately 100 MHz, and the anisotropic effect of the substrate was included in the design. In Section I1 the de- sign of the GAS using an anisotropic substrate will be dis- cussed. In Section I11 we will discuss methods for focus- ing the bulk acoustic wave in the transverse direction without the external lens. We also analyze the focus phase error, which is important for obtaining high resolution. To obtain large aperture operation and spherical aber- ration-free focusing, energy velocity dispersion in LiNb03 was calculated (given in the Appendix) and employed for designing the tap positions of a large time-bandwidth product, nonlinear chirp generator. The GAS was used in conjunction with a computer-controlled mechanical scan- ner, which scanned the sample in the transverse direction to the GAS to obtain two-dimensional images. This had not been achieved previously due to the lack of a stable mechanical scanner.
{"title":"Scanning Acoustic Microscope Utilizing SAW-BAW Conversion","authors":"Wen-Hsien Chen, F. Fu, Wei-Lee Lu","doi":"10.1109/T-SU.1985.31585","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31585","url":null,"abstract":"A 1WMHz acoustic microscope using an integrated grat- ing acoustic scanner is studied. The resolution of the system is approx- imately 68 pm. The real-time acoustic images obtained from this mi- croscope demonstrate the feasibility of the approach. The dependency of the energy velocity of acoustic waves on the propagation direction in the saggital plane of a Y-cut Z-propagating LiNbO, crystal was studied, and piezoelectric effects were included. The energy of velocity disper- sion was calculated and the results were employed for designing the tap positions of a large time-bandwidth product, nonlinear chirp fflter to obtain a large aperture and spherical aberration-free operation. Theoretical analysis reveals that for a given chirped waveform, the sur- face acoustic wave (SAW) propagating in the positive 2 direction gives better resolution than that in the negative 2 direction. Focusing the bulk acoustic wave in the transverse direction is achieved with the curved grooves or metallic strips, and the focus phase error using the curved structure are studied. to reduce the attenuation loss, and the crystals used are normally anisotropic. We had also previously reported a high-frequency GAS device (8) and demonstrated its fo- cusing and scanning capabilities. Electronic focusing in the axial direction was augmented by transverse focusing using an external lens that was massive and bulky. This device was operated at a rather high frequency, approximately 100 MHz, and the anisotropic effect of the substrate was included in the design. In Section I1 the de- sign of the GAS using an anisotropic substrate will be dis- cussed. In Section I11 we will discuss methods for focus- ing the bulk acoustic wave in the transverse direction without the external lens. We also analyze the focus phase error, which is important for obtaining high resolution. To obtain large aperture operation and spherical aber- ration-free focusing, energy velocity dispersion in LiNb03 was calculated (given in the Appendix) and employed for designing the tap positions of a large time-bandwidth product, nonlinear chirp generator. The GAS was used in conjunction with a computer-controlled mechanical scan- ner, which scanned the sample in the transverse direction to the GAS to obtain two-dimensional images. This had not been achieved previously due to the lack of a stable mechanical scanner.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130297672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Absrruci-In this paper a novel real-time tomographic system for imaging the nonlinear parameter B/A of biological objects is proposed. This parameter is related closely to the detailed structure and property of tissues, and may well provide a new dimensional and powerful tool for ultrasonic tissue characterization. In this system an impulsive, relatively high-power pumping wave is applied from a direction perpendiculax to the continuous low-intensity high-frequency probing wave so that the phase of the probing wave is modulated instantly by the product of the parameter B/A of the object and pressure of the pumping wave. Then the resulting spatially-modulated probing wave is detected and demodulated to derive the distribution of B/A along the probing beam. An inverse-filtering operation is employed to compensate for the spread of the pumping wave. The processes are repeated by shifting the position of the probing beam and a two-dimensional image is obtained. A prototype of the imaging system is constructed and images related to the nonlinear parameter of phantoms and human tissues are obtained. The usefulness of this method is shown in these experimental results.
{"title":"Real-Time Nonlinear Parameter Tomography Using Impulsive Pumping Waves","authors":"N. Ichida, T. Sato, H. Miwa, K. Murakami","doi":"10.1109/T-SU.1984.31548","DOIUrl":"https://doi.org/10.1109/T-SU.1984.31548","url":null,"abstract":"Absrruci-In this paper a novel real-time tomographic system for imaging the nonlinear parameter B/A of biological objects is proposed. This parameter is related closely to the detailed structure and property of tissues, and may well provide a new dimensional and powerful tool for ultrasonic tissue characterization. In this system an impulsive, relatively high-power pumping wave is applied from a direction perpendiculax to the continuous low-intensity high-frequency probing wave so that the phase of the probing wave is modulated instantly by the product of the parameter B/A of the object and pressure of the pumping wave. Then the resulting spatially-modulated probing wave is detected and demodulated to derive the distribution of B/A along the probing beam. An inverse-filtering operation is employed to compensate for the spread of the pumping wave. The processes are repeated by shifting the position of the probing beam and a two-dimensional image is obtained. A prototype of the imaging system is constructed and images related to the nonlinear parameter of phantoms and human tissues are obtained. The usefulness of this method is shown in these experimental results.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126636664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A simple theoretical model of trapped energy resonators with circular electrodes utilizing monoclinic crystal plates is presented. The effects due to ana nisotropic slowness curve for guided thicknesswaves in piezoelectric plates are included in this model so that it can be generally applied to the rotated Y-cut plates of quartz, LiTa03, or LiNb03. The theory is based on the "angular spectrum of plane waves" representation of two-dimensional thickness-wave solutions in the vicinity of the cutoff frequencies. Experimental measurements of resonant frequencies, vibrational patterns, and motional inductances on AT-cut quartz resonators are provided, and it is shown that calculations based on the theory are in excellent agreement with the results of experiments.
{"title":"Analysis of trapped energy resonators with circular electrodes","authors":"H. Sekimoto","doi":"10.1109/T-SU.1984.31553","DOIUrl":"https://doi.org/10.1109/T-SU.1984.31553","url":null,"abstract":"A simple theoretical model of trapped energy resonators with circular electrodes utilizing monoclinic crystal plates is presented. The effects due to ana nisotropic slowness curve for guided thicknesswaves in piezoelectric plates are included in this model so that it can be generally applied to the rotated Y-cut plates of quartz, LiTa03, or LiNb03. The theory is based on the \"angular spectrum of plane waves\" representation of two-dimensional thickness-wave solutions in the vicinity of the cutoff frequencies. Experimental measurements of resonant frequencies, vibrational patterns, and motional inductances on AT-cut quartz resonators are provided, and it is shown that calculations based on the theory are in excellent agreement with the results of experiments.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"404 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131892446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
cause the resultant wavefield is band-limited, the oversampled wavefield within the receiving aperture can be extrapolated over to an extended region. Then the resolution of the images can be considerably imh(x) = - exp (i2nr/~) cos + proved due to the extension of the aperture after extrapolation. (jAr)1'2 - 1z exp (j2nr/X)
{"title":"Resolution Enhancement by Wavefield Extrapolation","authors":"Hua Lee","doi":"10.1109/T-SU.1984.31549","DOIUrl":"https://doi.org/10.1109/T-SU.1984.31549","url":null,"abstract":"cause the resultant wavefield is band-limited, the oversampled wavefield within the receiving aperture can be extrapolated over to an extended region. Then the resolution of the images can be considerably imh(x) = - exp (i2nr/~) cos + proved due to the extension of the aperture after extrapolation. (jAr)1'2 - 1z exp (j2nr/X)","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130962460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The field scattered by a buried object is investigated as a function of various parameters of the object. An exact method based on an integral representation of the field is used to show the strong dependence of the field on the parameters. The possibility of characterizing the target from the knowledge of its scattered field is examined. An approximate method basedo n geometrical optics is introduced and its results are compared with those of the exact one. A simple representation of the field is provided by this method, which also allows the reconstruction of someo f the object parameters. Numerical results are given for objects with weak interactions, which are of interest in biomedical applications.
{"title":"Characterization of a buried cylindrical object from its scattered field","authors":"B. Duchêne, W. Tabbara","doi":"10.1109/T-SU.1984.31552","DOIUrl":"https://doi.org/10.1109/T-SU.1984.31552","url":null,"abstract":"The field scattered by a buried object is investigated as a function of various parameters of the object. An exact method based on an integral representation of the field is used to show the strong dependence of the field on the parameters. The possibility of characterizing the target from the knowledge of its scattered field is examined. An approximate method basedo n geometrical optics is introduced and its results are compared with those of the exact one. A simple representation of the field is provided by this method, which also allows the reconstruction of someo f the object parameters. Numerical results are given for objects with weak interactions, which are of interest in biomedical applications.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121856702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A theoretical and experimental investigation has been made of surface acoustic wave (SAW) timedelay change produced by the application of a dc electric field. Measurements were made on the three high-coupling cuts of lithium niobate for the electric field applied in the plane of the surface with a novel electrode configuration and normal-tothe- surface with a standard "convolver" plate. A theory has been developed for the normal field configuration, where the electric field is uniform, and for the in-plane case, where the field is nonuniform. The dominant contribution for the latterc omes from the center of the electrodes. For the 38 X-cut of lithium niobate, the normal field sensitivity (fractional timedelay change per applied electric field γ). is 141x10-12m/V, while γ for the in-plane field is 6x10-12m/V. The in-plane configuration has the advantage of having lower insertion loss and dispersion as the SAW does not have to propagate through a metal electrode. For 16.5° doubly rotated lithium niobate, a normal field device with a substrate thickness of 0.16 mm yielded a fractional timedelay change of 0.9x10-6/V. To our knowledge this is the largest time-delay change per applied voltage yet reported. The time-delay change is 10-4very linear with applied voltage; the second derivative is typically multiplied by slope. Both electrode configurations yield monolithic devices that dissipate no dc power.
{"title":"Electrostatically variable saw delay lines - Theory and experiment","authors":"A. Budreau, G. Scalzi, P. Carr, H. Bertoni","doi":"10.1109/T-SU.1984.31550","DOIUrl":"https://doi.org/10.1109/T-SU.1984.31550","url":null,"abstract":"A theoretical and experimental investigation has been made of surface acoustic wave (SAW) timedelay change produced by the application of a dc electric field. Measurements were made on the three high-coupling cuts of lithium niobate for the electric field applied in the plane of the surface with a novel electrode configuration and normal-tothe- surface with a standard \"convolver\" plate. A theory has been developed for the normal field configuration, where the electric field is uniform, and for the in-plane case, where the field is nonuniform. The dominant contribution for the latterc omes from the center of the electrodes. For the 38 X-cut of lithium niobate, the normal field sensitivity (fractional timedelay change per applied electric field γ). is 141x10-12m/V, while γ for the in-plane field is 6x10-12m/V. The in-plane configuration has the advantage of having lower insertion loss and dispersion as the SAW does not have to propagate through a metal electrode. For 16.5° doubly rotated lithium niobate, a normal field device with a substrate thickness of 0.16 mm yielded a fractional timedelay change of 0.9x10-6/V. To our knowledge this is the largest time-delay change per applied voltage yet reported. The time-delay change is 10-4very linear with applied voltage; the second derivative is typically multiplied by slope. Both electrode configurations yield monolithic devices that dissipate no dc power.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114209737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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